canvas.cc revision 3551c9c881056c480085172ff9840cab31610854 
1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "ui/gfx/canvas.h"
6
7#include <limits>
8
9#include "base/i18n/rtl.h"
10#include "base/logging.h"
11#include "third_party/skia/include/core/SkBitmap.h"
12#include "third_party/skia/include/effects/SkGradientShader.h"
13#include "ui/gfx/canvas.h"
14#include "ui/gfx/font_list.h"
15#include "ui/gfx/rect.h"
16#include "ui/gfx/size_conversions.h"
17#include "ui/gfx/skia_util.h"
18#include "ui/gfx/transform.h"
19
20#if defined(OS_WIN)
21#include "ui/gfx/canvas_skia_paint.h"
22#endif
23
24namespace gfx {
25
26Canvas::Canvas(const Size& size, ui::ScaleFactor scale_factor, bool is_opaque)
27    : scale_factor_(scale_factor),
28      canvas_(NULL) {
29  Size pixel_size = ToCeiledSize(
30      ScaleSize(size, ui::GetScaleFactorScale(scale_factor)));
31  owned_canvas_ = skia::AdoptRef(skia::CreatePlatformCanvas(pixel_size.width(),
32                                                            pixel_size.height(),
33                                                            is_opaque));
34  canvas_ = owned_canvas_.get();
35#if defined(OS_WIN) || defined(OS_MACOSX)
36  // skia::PlatformCanvas instances are initialized to 0 by Cairo on Linux, but
37  // uninitialized on Win and Mac.
38  if (!is_opaque)
39    owned_canvas_->clear(SkColorSetARGB(0, 0, 0, 0));
40#endif
41
42  SkScalar scale = SkFloatToScalar(ui::GetScaleFactorScale(scale_factor));
43  canvas_->scale(scale, scale);
44}
45
46Canvas::Canvas(const ImageSkiaRep& image_rep, bool is_opaque)
47    : scale_factor_(image_rep.scale_factor()),
48      owned_canvas_(skia::AdoptRef(
49          skia::CreatePlatformCanvas(image_rep.pixel_width(),
50                                     image_rep.pixel_height(),
51                                     is_opaque))),
52      canvas_(owned_canvas_.get()) {
53  SkScalar scale = SkFloatToScalar(ui::GetScaleFactorScale(scale_factor_));
54  canvas_->scale(scale, scale);
55  DrawImageInt(ImageSkia(image_rep), 0, 0);
56}
57
58Canvas::Canvas()
59    : scale_factor_(ui::SCALE_FACTOR_100P),
60      owned_canvas_(skia::AdoptRef(skia::CreatePlatformCanvas(0, 0, false))),
61      canvas_(owned_canvas_.get()) {
62}
63
64Canvas::~Canvas() {
65}
66
67// static
68Canvas* Canvas::CreateCanvasWithoutScaling(SkCanvas* canvas,
69                                           ui::ScaleFactor scale_factor) {
70  return new Canvas(canvas, scale_factor);
71}
72
73void Canvas::RecreateBackingCanvas(const Size& size,
74                                   ui::ScaleFactor scale_factor,
75                                   bool is_opaque) {
76  scale_factor_ = scale_factor;
77  Size pixel_size = ToFlooredSize(
78      ScaleSize(size, ui::GetScaleFactorScale(scale_factor)));
79  owned_canvas_ = skia::AdoptRef(skia::CreatePlatformCanvas(pixel_size.width(),
80                                                            pixel_size.height(),
81                                                            is_opaque));
82  canvas_ = owned_canvas_.get();
83  SkScalar scale = SkFloatToScalar(ui::GetScaleFactorScale(scale_factor_));
84  canvas_->scale(scale, scale);
85}
86
87// static
88void Canvas::SizeStringInt(const base::string16& text,
89                           const Font& font,
90                           int* width,
91                           int* height,
92                           int line_height,
93                           int flags) {
94  SizeStringInt(text, FontList(font), width, height, line_height, flags);
95}
96
97// static
98int Canvas::GetStringWidth(const base::string16& text,
99                           const FontList& font_list) {
100  int width = 0, height = 0;
101  SizeStringInt(text, font_list, &width, &height, 0, NO_ELLIPSIS);
102  return width;
103}
104
105// static
106int Canvas::GetStringWidth(const base::string16& text, const Font& font) {
107  int width = 0, height = 0;
108  SizeStringInt(text, FontList(font), &width, &height, 0, NO_ELLIPSIS);
109  return width;
110}
111
112// static
113int Canvas::DefaultCanvasTextAlignment() {
114  return base::i18n::IsRTL() ? TEXT_ALIGN_RIGHT : TEXT_ALIGN_LEFT;
115}
116
117void Canvas::DrawStringWithHalo(const base::string16& text,
118                                const Font& font,
119                                SkColor text_color,
120                                SkColor halo_color_in,
121                                int x,
122                                int y,
123                                int w,
124                                int h,
125                                int flags) {
126  DrawStringRectWithHalo(text, FontList(font), text_color, halo_color_in,
127                         Rect(x, y, w, h), flags);
128}
129
130ImageSkiaRep Canvas::ExtractImageRep() const {
131  const SkBitmap& device_bitmap = canvas_->getDevice()->accessBitmap(false);
132
133  // Make a bitmap to return, and a canvas to draw into it. We don't just want
134  // to call extractSubset or the copy constructor, since we want an actual copy
135  // of the bitmap.
136  SkBitmap result;
137  device_bitmap.copyTo(&result, SkBitmap::kARGB_8888_Config);
138
139  return ImageSkiaRep(result, scale_factor_);
140}
141
142void Canvas::DrawDashedRect(const Rect& rect, SkColor color) {
143  // Create a 2D bitmap containing alternating on/off pixels - we do this
144  // so that you never get two pixels of the same color around the edges
145  // of the focus rect (this may mean that opposing edges of the rect may
146  // have a dot pattern out of phase to each other).
147  static SkColor last_color;
148  static SkBitmap* dots = NULL;
149  if (!dots || last_color != color) {
150    int col_pixels = 32;
151    int row_pixels = 32;
152
153    delete dots;
154    last_color = color;
155    dots = new SkBitmap;
156    dots->setConfig(SkBitmap::kARGB_8888_Config, col_pixels, row_pixels);
157    dots->allocPixels();
158    dots->eraseARGB(0, 0, 0, 0);
159
160    uint32_t* dot = dots->getAddr32(0, 0);
161    for (int i = 0; i < row_pixels; i++) {
162      for (int u = 0; u < col_pixels; u++) {
163        if ((u % 2 + i % 2) % 2 != 0) {
164          dot[i * row_pixels + u] = color;
165        }
166      }
167    }
168  }
169
170  // Make a shader for the bitmap with an origin of the box we'll draw. This
171  // shader is refcounted and will have an initial refcount of 1.
172  skia::RefPtr<SkShader> shader = skia::AdoptRef(
173      SkShader::CreateBitmapShader(
174          *dots, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode));
175  // Assign the shader to the paint & release our reference. The paint will
176  // now own the shader and the shader will be destroyed when the paint goes
177  // out of scope.
178  SkPaint paint;
179  paint.setShader(shader.get());
180
181  DrawRect(Rect(rect.x(), rect.y(), rect.width(), 1), paint);
182  DrawRect(Rect(rect.x(), rect.y() + rect.height() - 1, rect.width(), 1),
183           paint);
184  DrawRect(Rect(rect.x(), rect.y(), 1, rect.height()), paint);
185  DrawRect(Rect(rect.x() + rect.width() - 1, rect.y(), 1, rect.height()),
186           paint);
187}
188
189void Canvas::Save() {
190  canvas_->save();
191}
192
193void Canvas::SaveLayerAlpha(uint8 alpha) {
194  canvas_->saveLayerAlpha(NULL, alpha);
195}
196
197
198void Canvas::SaveLayerAlpha(uint8 alpha, const Rect& layer_bounds) {
199  SkRect bounds(RectToSkRect(layer_bounds));
200  canvas_->saveLayerAlpha(&bounds, alpha);
201}
202
203void Canvas::Restore() {
204  canvas_->restore();
205}
206
207bool Canvas::ClipRect(const Rect& rect) {
208  return canvas_->clipRect(RectToSkRect(rect));
209}
210
211bool Canvas::ClipPath(const SkPath& path) {
212  return canvas_->clipPath(path);
213}
214
215bool Canvas::GetClipBounds(Rect* bounds) {
216  SkRect out;
217  bool has_non_empty_clip = canvas_->getClipBounds(&out);
218  bounds->SetRect(out.left(), out.top(), out.width(), out.height());
219  return has_non_empty_clip;
220}
221
222void Canvas::Translate(const Vector2d& offset) {
223  canvas_->translate(SkIntToScalar(offset.x()), SkIntToScalar(offset.y()));
224}
225
226void Canvas::Scale(int x_scale, int y_scale) {
227  canvas_->scale(SkIntToScalar(x_scale), SkIntToScalar(y_scale));
228}
229
230void Canvas::DrawColor(SkColor color) {
231  DrawColor(color, SkXfermode::kSrcOver_Mode);
232}
233
234void Canvas::DrawColor(SkColor color, SkXfermode::Mode mode) {
235  canvas_->drawColor(color, mode);
236}
237
238void Canvas::FillRect(const Rect& rect, SkColor color) {
239  FillRect(rect, color, SkXfermode::kSrcOver_Mode);
240}
241
242void Canvas::FillRect(const Rect& rect,
243                      SkColor color,
244                      SkXfermode::Mode mode) {
245  SkPaint paint;
246  paint.setColor(color);
247  paint.setStyle(SkPaint::kFill_Style);
248  paint.setXfermodeMode(mode);
249  DrawRect(rect, paint);
250}
251
252void Canvas::DrawRect(const Rect& rect, SkColor color) {
253  DrawRect(rect, color, SkXfermode::kSrcOver_Mode);
254}
255
256void Canvas::DrawRect(const Rect& rect,
257                      SkColor color,
258                      SkXfermode::Mode mode) {
259  SkPaint paint;
260  paint.setColor(color);
261  paint.setStyle(SkPaint::kStroke_Style);
262  // Set a stroke width of 0, which will put us down the stroke rect path.  If
263  // we set a stroke width of 1, for example, this will internally create a
264  // path and fill it, which causes problems near the edge of the canvas.
265  paint.setStrokeWidth(SkIntToScalar(0));
266  paint.setXfermodeMode(mode);
267
268  DrawRect(rect, paint);
269}
270
271void Canvas::DrawRect(const Rect& rect, const SkPaint& paint) {
272  canvas_->drawIRect(RectToSkIRect(rect), paint);
273}
274
275void Canvas::DrawPoint(const Point& p1, const SkPaint& paint) {
276  canvas_->drawPoint(SkIntToScalar(p1.x()), SkIntToScalar(p1.y()), paint);
277}
278
279void Canvas::DrawLine(const Point& p1, const Point& p2, SkColor color) {
280  SkPaint paint;
281  paint.setColor(color);
282  paint.setStrokeWidth(SkIntToScalar(1));
283  DrawLine(p1, p2, paint);
284}
285
286void Canvas::DrawLine(const Point& p1, const Point& p2, const SkPaint& paint) {
287  canvas_->drawLine(SkIntToScalar(p1.x()), SkIntToScalar(p1.y()),
288                    SkIntToScalar(p2.x()), SkIntToScalar(p2.y()), paint);
289}
290
291void Canvas::DrawCircle(const Point& center_point,
292                        int radius,
293                        const SkPaint& paint) {
294  canvas_->drawCircle(SkIntToScalar(center_point.x()),
295      SkIntToScalar(center_point.y()), SkIntToScalar(radius), paint);
296}
297
298void Canvas::DrawRoundRect(const Rect& rect,
299                           int radius,
300                           const SkPaint& paint) {
301  canvas_->drawRoundRect(RectToSkRect(rect), SkIntToScalar(radius),
302                         SkIntToScalar(radius), paint);
303}
304
305void Canvas::DrawPath(const SkPath& path, const SkPaint& paint) {
306  canvas_->drawPath(path, paint);
307}
308
309void Canvas::DrawFocusRect(const Rect& rect) {
310  DrawDashedRect(rect, SK_ColorGRAY);
311}
312
313void Canvas::DrawImageInt(const ImageSkia& image, int x, int y) {
314  SkPaint paint;
315  DrawImageInt(image, x, y, paint);
316}
317
318void Canvas::DrawImageInt(const ImageSkia& image, int x, int y, uint8 a) {
319  SkPaint paint;
320  paint.setAlpha(a);
321  DrawImageInt(image, x, y, paint);
322}
323
324void Canvas::DrawImageInt(const ImageSkia& image,
325                          int x,
326                          int y,
327                          const SkPaint& paint) {
328  const ImageSkiaRep& image_rep = GetImageRepToPaint(image);
329  if (image_rep.is_null())
330    return;
331  const SkBitmap& bitmap = image_rep.sk_bitmap();
332  float bitmap_scale = image_rep.GetScale();
333
334  canvas_->save();
335  canvas_->scale(SkFloatToScalar(1.0f / bitmap_scale),
336                 SkFloatToScalar(1.0f / bitmap_scale));
337  canvas_->drawBitmap(bitmap,
338                      SkFloatToScalar(x * bitmap_scale),
339                      SkFloatToScalar(y * bitmap_scale),
340                      &paint);
341  canvas_->restore();
342}
343
344void Canvas::DrawImageInt(const ImageSkia& image,
345                          int src_x,
346                          int src_y,
347                          int src_w,
348                          int src_h,
349                          int dest_x,
350                          int dest_y,
351                          int dest_w,
352                          int dest_h,
353                          bool filter) {
354  SkPaint p;
355  DrawImageInt(image, src_x, src_y, src_w, src_h, dest_x, dest_y,
356               dest_w, dest_h, filter, p);
357}
358
359void Canvas::DrawImageInt(const ImageSkia& image,
360                          int src_x,
361                          int src_y,
362                          int src_w,
363                          int src_h,
364                          int dest_x,
365                          int dest_y,
366                          int dest_w,
367                          int dest_h,
368                          bool filter,
369                          const SkPaint& paint) {
370  DLOG_ASSERT(src_x + src_w < std::numeric_limits<int16_t>::max() &&
371              src_y + src_h < std::numeric_limits<int16_t>::max());
372  if (src_w <= 0 || src_h <= 0) {
373    NOTREACHED() << "Attempting to draw bitmap from an empty rect!";
374    return;
375  }
376
377  if (!IntersectsClipRectInt(dest_x, dest_y, dest_w, dest_h))
378    return;
379
380  float user_scale_x = static_cast<float>(dest_w) / src_w;
381  float user_scale_y = static_cast<float>(dest_h) / src_h;
382
383  const ImageSkiaRep& image_rep = GetImageRepToPaint(image,
384      user_scale_x, user_scale_y);
385  if (image_rep.is_null())
386    return;
387
388  SkRect dest_rect = { SkIntToScalar(dest_x),
389                       SkIntToScalar(dest_y),
390                       SkIntToScalar(dest_x + dest_w),
391                       SkIntToScalar(dest_y + dest_h) };
392
393  if (src_w == dest_w && src_h == dest_h &&
394      user_scale_x == 1.0f && user_scale_y == 1.0f &&
395      image_rep.scale_factor() == ui::SCALE_FACTOR_100P) {
396    // Workaround for apparent bug in Skia that causes image to occasionally
397    // shift.
398    SkIRect src_rect = { src_x, src_y, src_x + src_w, src_y + src_h };
399    const SkBitmap& bitmap = image_rep.sk_bitmap();
400    canvas_->drawBitmapRect(bitmap, &src_rect, dest_rect, &paint);
401    return;
402  }
403
404  // Make a bitmap shader that contains the bitmap we want to draw. This is
405  // basically what SkCanvas.drawBitmap does internally, but it gives us
406  // more control over quality and will use the mipmap in the source image if
407  // it has one, whereas drawBitmap won't.
408  SkMatrix shader_scale;
409  shader_scale.setScale(SkFloatToScalar(user_scale_x),
410                        SkFloatToScalar(user_scale_y));
411  shader_scale.preTranslate(SkIntToScalar(-src_x), SkIntToScalar(-src_y));
412  shader_scale.postTranslate(SkIntToScalar(dest_x), SkIntToScalar(dest_y));
413
414  skia::RefPtr<SkShader> shader = CreateImageRepShader(
415      image_rep,
416      SkShader::kRepeat_TileMode,
417      shader_scale);
418
419  // Set up our paint to use the shader & release our reference (now just owned
420  // by the paint).
421  SkPaint p(paint);
422  p.setFilterBitmap(filter);
423  p.setShader(shader.get());
424
425  // The rect will be filled by the bitmap.
426  canvas_->drawRect(dest_rect, p);
427}
428
429void Canvas::DrawImageInPath(const ImageSkia& image,
430                             int x,
431                             int y,
432                             const SkPath& path,
433                             const SkPaint& paint) {
434  const ImageSkiaRep& image_rep = GetImageRepToPaint(image);
435  if (image_rep.is_null())
436    return;
437
438  SkMatrix matrix;
439  matrix.setTranslate(SkIntToScalar(x), SkIntToScalar(y));
440  skia::RefPtr<SkShader> shader = CreateImageRepShader(
441      image_rep,
442      SkShader::kRepeat_TileMode,
443      matrix);
444
445  SkPaint p(paint);
446  p.setShader(shader.get());
447  canvas_->drawPath(path, p);
448}
449
450void Canvas::DrawStringRect(const base::string16& text,
451                            const FontList& font_list,
452                            SkColor color,
453                            const Rect& display_rect) {
454  DrawStringRectWithFlags(text, font_list, color, display_rect,
455                          DefaultCanvasTextAlignment());
456}
457
458void Canvas::DrawStringRectWithFlags(const base::string16& text,
459                                     const FontList& font_list,
460                                     SkColor color,
461                                     const Rect& display_rect,
462                                     int flags) {
463  DrawStringRectWithShadows(text, font_list, color, display_rect, 0, flags,
464                            ShadowValues());
465}
466
467void Canvas::DrawStringInt(const base::string16& text,
468                           const Font& font,
469                           SkColor color,
470                           int x,
471                           int y,
472                           int w,
473                           int h) {
474  DrawStringInt(text, font, color, x, y, w, h, DefaultCanvasTextAlignment());
475}
476
477void Canvas::DrawStringInt(const base::string16& text,
478                           const Font& font,
479                           SkColor color,
480                           const Rect& display_rect) {
481  DrawStringInt(text, font, color, display_rect.x(), display_rect.y(),
482                display_rect.width(), display_rect.height());
483}
484
485void Canvas::DrawStringInt(const base::string16& text,
486                           const Font& font,
487                           SkColor color,
488                           int x,
489                           int y,
490                           int w,
491                           int h,
492                           int flags) {
493  DrawStringWithShadows(text, font, color, Rect(x, y, w, h), 0, flags,
494                        ShadowValues());
495}
496
497void Canvas::DrawStringWithShadows(const base::string16& text,
498                                   const Font& font,
499                                   SkColor color,
500                                   const Rect& text_bounds,
501                                   int line_height,
502                                   int flags,
503                                   const ShadowValues& shadows) {
504  DrawStringRectWithShadows(text, FontList(font), color, text_bounds,
505                            line_height, flags, shadows);
506}
507
508void Canvas::TileImageInt(const ImageSkia& image,
509                          int x,
510                          int y,
511                          int w,
512                          int h) {
513  TileImageInt(image, 0, 0, x, y, w, h);
514}
515
516void Canvas::TileImageInt(const ImageSkia& image,
517                          int src_x,
518                          int src_y,
519                          int dest_x,
520                          int dest_y,
521                          int w,
522                          int h) {
523  TileImageInt(image, src_x, src_y, 1.0f, 1.0f, dest_x, dest_y, w, h);
524}
525
526void Canvas::TileImageInt(const ImageSkia& image,
527                          int src_x,
528                          int src_y,
529                          float tile_scale_x,
530                          float tile_scale_y,
531                          int dest_x,
532                          int dest_y,
533                          int w,
534                          int h) {
535  if (!IntersectsClipRectInt(dest_x, dest_y, w, h))
536    return;
537
538  const ImageSkiaRep& image_rep = GetImageRepToPaint(
539      image, tile_scale_x, tile_scale_y);
540  if (image_rep.is_null())
541    return;
542
543  SkMatrix shader_scale;
544  shader_scale.setScale(SkFloatToScalar(tile_scale_x),
545                        SkFloatToScalar(tile_scale_y));
546  shader_scale.preTranslate(SkIntToScalar(-src_x), SkIntToScalar(-src_y));
547  shader_scale.postTranslate(SkIntToScalar(dest_x), SkIntToScalar(dest_y));
548
549  skia::RefPtr<SkShader> shader = CreateImageRepShader(
550      image_rep,
551      SkShader::kRepeat_TileMode,
552      shader_scale);
553
554  SkPaint paint;
555  paint.setShader(shader.get());
556  paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
557
558  SkRect dest_rect = { SkIntToScalar(dest_x),
559                       SkIntToScalar(dest_y),
560                       SkIntToScalar(dest_x + w),
561                       SkIntToScalar(dest_y + h) };
562  canvas_->drawRect(dest_rect, paint);
563}
564
565NativeDrawingContext Canvas::BeginPlatformPaint() {
566  return skia::BeginPlatformPaint(canvas_);
567}
568
569void Canvas::EndPlatformPaint() {
570  skia::EndPlatformPaint(canvas_);
571}
572
573void Canvas::Transform(const gfx::Transform& transform) {
574  canvas_->concat(transform.matrix());
575}
576
577Canvas::Canvas(SkCanvas* canvas, ui::ScaleFactor scale_factor)
578    : scale_factor_(scale_factor),
579      owned_canvas_(),
580      canvas_(canvas) {
581  DCHECK(canvas);
582}
583
584bool Canvas::IntersectsClipRectInt(int x, int y, int w, int h) {
585  SkRect clip;
586  return canvas_->getClipBounds(&clip) &&
587      clip.intersect(SkIntToScalar(x), SkIntToScalar(y), SkIntToScalar(x + w),
588                     SkIntToScalar(y + h));
589}
590
591bool Canvas::IntersectsClipRect(const Rect& rect) {
592  return IntersectsClipRectInt(rect.x(), rect.y(),
593                               rect.width(), rect.height());
594}
595
596const ImageSkiaRep& Canvas::GetImageRepToPaint(const ImageSkia& image) const {
597  return GetImageRepToPaint(image, 1.0f, 1.0f);
598}
599
600const ImageSkiaRep& Canvas::GetImageRepToPaint(
601    const ImageSkia& image,
602    float user_additional_scale_x,
603    float user_additional_scale_y) const {
604  const ImageSkiaRep& image_rep = image.GetRepresentation(scale_factor_);
605
606  if (!image_rep.is_null()) {
607    SkMatrix m = canvas_->getTotalMatrix();
608    float scale_x = SkScalarToFloat(SkScalarAbs(m.getScaleX())) *
609        user_additional_scale_x;
610    float scale_y = SkScalarToFloat(SkScalarAbs(m.getScaleY())) *
611        user_additional_scale_y;
612
613    float bitmap_scale = image_rep.GetScale();
614    if (scale_x < bitmap_scale || scale_y < bitmap_scale)
615      const_cast<SkBitmap&>(image_rep.sk_bitmap()).buildMipMap();
616  }
617
618  return image_rep;
619}
620
621}  // namespace gfx
622